As conventional examples of the steering column device capable of a tilt and telescopic operation, there are constitutions disclosed in Patent Document 1 (JP 2001-347953 A) and Patent Document 2 (EP 1910148 B1). Each of these steering column devices includes a tilt-position adjustment mechanism for performing positional adjustment of a steering wheel in a vehicle vertical direction and a telescopic-position adjustment mechanism for performing positional adjustment of the steering wheel in a vehicle longitudinal direction.
The steering column device of Patent Document 1 includes an attachment bracket fixed on the side of a vehicle body, an outer column having a cylindrical shape and arranged between a pair of hanging parts constituting the attachment bracket along the vehicle longitudinal direction, an inner column arranged movably in a cylinder of the outer column along the vehicle longitudinal direction, and a fastening member for fixing the inner column and the outer column in arbitrary positions. The outer column is provided with a slit penetrating through a cylinder wall of the outer column Since the fastening member operates to reduce the diameter of the outer column while narrowing the gap of the slit from the outside of the hanging parts in pairs, they are brought into pressure contact with the outer column and then, it is brought into pressure contact with the inner column, thereby fixing the outer column and the inner column to an arbitrary position.
Also in the steering column device of Patent Document 2, similarly to Patent Document 1, since the fastening member narrows the interval of a pair of parallel-upstanding side plates from the outside of a pair of hanging parts, the hanging parts are brought into pressure contact with the outer column and then, it is brought into contact with the inner column, thereby fixing the outer column and the inner column to an arbitrary position.